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Trial registered on ANZCTR


Registration number
ACTRN12622000833763
Ethics application status
Approved
Date submitted
3/06/2022
Date registered
14/06/2022
Date last updated
14/06/2022
Date data sharing statement initially provided
14/06/2022
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of personalised lighting recommendations on sleep and alertness in shift workers
Scientific title
The effect of personalised lighting recommendations on circadian adaptation, sleep, and alertness in shift workers
Secondary ID [1] 307104 0
None
Universal Trial Number (UTN)
Trial acronym
SWITCH: Shift Workers' Individualised Treatments for Circadian Health
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Shift Work 326296 0
Circadian Misalignment 326297 0
Sleep loss 326298 0
Sleepiness 326299 0
Condition category
Condition code
Public Health 323608 323608 0 0
Health promotion/education
Neurological 323609 323609 0 0
Other neurological disorders
Mental Health 323610 323610 0 0
Other mental health disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The project will provide workers with personalised recommendations on when to seek light and when to avoid light.

Study duration: up to 8 weeks. Participants will be monitored for 3 weeks at the start and 3 weeks at the end, with a 2-week break in the middle. Participants will follow the lighting recommendations in week 7. The study duration and exact timings/ dates of the recommendations will depend on participants' shift schedule/ rosters.

All data from the initial 3-week monitoring will be used to personalise the recommendations. This includes participants' habitual sleep (from baseline survey), circadian timing, typical sleep and light exposure, upcoming work roster and personal commitments.

The personalised recommendations will be delivered via a handout with written recommendations. The lighting recommendations will start (and finish) 1-2 days before (and after) participants' first (and final) night/ early morning shift for the particular shift rotation. The duration of how long participants follow the recommendations will depend on each participant's roster (e.g., one participant may have 4 consecutive night shifts, whereas another participant has 3 consecutive night shifts).

Lighting devices will be provided that suit specific working conditions (e.g., light-emitting glasses - Luminette 3; or light boxes at work stations - HappyLamp). Both device emit light that is up to 10,000 lux and are polychromatic white lights.

Participants will be provided with blue-light blocking sunglasses (Block Blue Light:
NightFall Wayfarer Blue Blocking Glasses/ NightFall Premium FITOVER Blue Blocking Glasses)
to wear after finishing early morning/ night shifts.

The duration for which participants will be instructed to use the blue-light blocking sunglasses and light-emitting device will differ for each participant as each intervention is personalised. As an example, one participant may be recommended to: (1) between DATE1 - DATE2, wear the blue-light blocking sunglasses as much as possible from the time of shift completion until going to sleep (but not when driving). (2) Between DATE1-DATE2, use the Luminette device as much as possible when you are on night shifts. (3) Between DATE1-DATE2 on your days off, use the Luminette device between 10am-12pm.

Participants will complete daily surveys to self-report the timings of when they used the light-emitting device and blue-light blocking sunglasses.
Intervention code [1] 323584 0
Lifestyle
Intervention code [2] 323585 0
Behaviour
Intervention code [3] 323586 0
Treatment: Devices
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 331412 0
Circadian timing (concentration of 6-hydroxymelatonin sulfate (aMT6) in urine samples across the 48-hour collection)
Timepoint [1] 331412 0
Circadian timing is assessed pre-intervention and during the intervention:
(1) 2 x 48-hour urine collection during shift rotation at baseline (pre-intervention)
(2) 2 x 48-hour urine collection during shift rotation during the intervention (week 5 and week 7 of the 8-week study)
Primary outcome [2] 331413 0
Sleep duration and quality will be measured using actigraphy and daily sleep diaries (adapted from Consensus Sleep Diary). A composite primary outcome will be generated by using sleep diaries to confirm actigraphy sleep and wake timings.
Timepoint [2] 331413 0
Monitored daily during shift rotation over a period of up to 3 weeks at baseline (pre-intervention), and during the subsequent shift rotation over a period of up to 3 weeks post-intervention commencement,
Primary outcome [3] 331414 0
Sleepiness (Karolinska Sleepiness Scale)
Timepoint [3] 331414 0
Completed 3 times for every shift:
1) Start of shift
2) Middle of shift
3) End of work shift
Secondary outcome [1] 409768 0
Depression, Anxiety and Stress Scale - 21 Items (DASS-21)
Timepoint [1] 409768 0
Baseline and End-of-study (at the completion of the shift rotation up to 3 weeks post-intervention/ last week of study)
Secondary outcome [2] 409769 0
Insomnia Severity Index
Timepoint [2] 409769 0
Baseline and End-of-study (at the completion of the shift rotation up to 3 weeks post-intervention/ last week of study)
Secondary outcome [3] 410584 0
Daily patterns of light exposure (measured via a light pendant (ActTrust, model code AT0503LF, Condor Instruments, Brazil).
Timepoint [3] 410584 0
Monitored daily during shift rotation over a period of up to 3 weeks at baseline (pre-intervention), and during the subsequent shift rotation over a period of up to 3 weeks post-intervention commencement,
Secondary outcome [4] 410585 0
Daily sleepiness when driving to and from work (Karolinska Sleepiness Scale, completed before and after every drive).
Timepoint [4] 410585 0
Monitored daily during shift rotation over a period of up to 3 weeks at baseline (pre-intervention), and during the subsequent shift rotation over a period of up to 3 weeks post-intervention commencement,

Eligibility
Key inclusion criteria
(1) aged 18-65 years,
(2) at least 4 night or early morning shifts worked a month on average
- with night work defined as at least 6 hours worked between 2200h and 0800h
- early morning work defined as starting work before 0700h
(3) a roster pattern incorporating at least 3 consecutive night or early morning shifts
Minimum age
18 Years
Maximum age
65 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Individuals with the following conditions that may impact the main outcomes of the study (internal circadian pacemaker, sleep, or light sensitivity) will be excluded:
1. Have a prior and untreated diagnosis, and/or a current diagnosis of a sleep disorder other than insomnia
2. Are using drugs known to impact sleep, alertness, or the circadian pacemaker (i.e., body clock)
3. Have visual disorders, or history of eye surgery or laser correction
4. Epilepsy, photosensitivity, or have been recommended by a health professional to avoid bright light.
5. Wear prescription glasses with coloured lenses or transition lenses (i.e., lenses that automatically darken in bright light).
6. Report high daytime sleepiness on a short survey (i.e., Epworth Sleepiness Scale score > 16), and typically drive themselves to and from work after early morning/ night shifts

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
12/07/2022
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
100
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 311411 0
Government body
Name [1] 311411 0
National Health and Medical Research Council (NHMRC)
Country [1] 311411 0
Australia
Primary sponsor type
University
Name
Monash University
Address
Ground Floor, Be Active Sleep Eat (BASE) facility
270 Ferntree Gully Road,
NOTTING HILL VIC 3168
Country
Australia
Secondary sponsor category [1] 312800 0
Other
Name [1] 312800 0
Institute for Breathing and Sleep
Address [1] 312800 0
145 Studley Rd, Heidelberg VIC 3084
Country [1] 312800 0
Australia
Secondary sponsor category [2] 312864 0
University
Name [2] 312864 0
The University of Sydney
Address [2] 312864 0
Camperdown NSW 2006
Country [2] 312864 0
Australia
Secondary sponsor category [3] 312865 0
University
Name [3] 312865 0
Harvard Medical School
Address [3] 312865 0
25 Shattuck St, Boston, MA 02115, United States
Country [3] 312865 0
United States of America

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 310890 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 310890 0
Wellington Road, Clayton VIC 3800
Ethics committee country [1] 310890 0
Australia
Date submitted for ethics approval [1] 310890 0
Approval date [1] 310890 0
22/06/2021
Ethics approval number [1] 310890 0
28948

Summary
Brief summary
Shift work often leads to poor sleep and wellbeing, fatigue and increased risks of road and workplace accidents. Employees are often impacted differently by shift work and the individual pattern of light exposure plays a crucial role in determining how the body clock responds. There is a need for personalised approaches to the management of sleep and health in shift workers.

The project will provide personalised lighting recommendations to shift the timing of worker’s body clocks and help them better adapt to their specific shift work schedules. The strategic light exposure, based on scientific evidence, will target improved sleep, alertness, performance, and wellbeing.

Shift workers will participate for up to 8 weeks, depending on their shift schedule. For one shift rotation (first 3 weeks of study), participants will complete short daily questions on sleep and alertness via a smartphone app, and wear a wrist-watch activity monitor and small pendant on their lapel to monitor sleep and light exposure. They will also have their body clock timing measured twice.

Based on this monitoring, each participant will be provided with personalised recommendations on when to seek light and when to avoid light during a subsequent shift rotation (last 3 weeks of study). Lighting devices will be provided that suit specific working conditions (e.g., light-emitting glasses or light boxes at work stations). Monitoring of sleep, alertness, light and body clock timing will be repeated to demonstrate the impact of the personalised recommendations.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 119246 0
Dr Tracey Sletten
Address 119246 0
Ground Floor, BASE Facility
270 Ferntree Gully Road
Notting Hill, VIC 3168
Country 119246 0
Australia
Phone 119246 0
+61 399020734
Fax 119246 0
Email 119246 0
tracey.sletten@monash.edu
Contact person for public queries
Name 119247 0
Dr Tracey Sletten
Address 119247 0
Ground Floor, BASE Facility
270 Ferntree Gully Road
Notting Hill, VIC 3168
Country 119247 0
Australia
Phone 119247 0
+61 399020734
Fax 119247 0
Email 119247 0
tracey.sletten@monash.edu
Contact person for scientific queries
Name 119248 0
Dr Tracey Sletten
Address 119248 0
Ground Floor, BASE Facility
270 Ferntree Gully Road
Notting Hill, VIC 3168
Country 119248 0
Australia
Phone 119248 0
+61 399020734
Fax 119248 0
Email 119248 0
tracey.sletten@monash.edu

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Individual participant data will not be shared


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.